Centrifugal purifier



1967 D. ALSOBROOKS 3,347,380

CENTRIFUGAL PURIFIER Filed Oct. 23, 1965 INVENTOR. zza 4. fl/saZraaZs )7 rain L745:

United States Patent Ofiice 3,347,380 CENTRIFUGAL PURIFIER Darriel L. Alsobrooks, Grosse Ile, Mich., assignor to Michigan Dynamics, Inc., a corporation of Michigan Filed Oct. 23, 1965, Ser. No. 503,722 11 Claims. (Cl. 210--130) ABSTRACT OF THE DISCLOSURE This application discloses a centrifugal purifier including an impeller that drives heavier contaminants from a fluid as it passes through the purifier. In addition, a rotating perforate member is interposed in the path of fluid flow so as to prevent passage of particles larger than a predetermined size through the purifier. A bypass arrangement is also incorporated for bypassing the fluid flow through the perforate member when it becomes clogged with contaminants without interfering with the operation of the centrifugal impeller.

This invention relates to a centrifugal purifier for extracting particles larger than a given size from a fluid and more particularly to a bypass valve for such a purifier that insures against a stoppage in flow if the purifier becomes obstructed with contaminants.

In the copending United States patent application of Rex C. Darnell, Ser. No. 503,924, filed Oct. 23, 1965, entitled Purifier and assigned to the assignee of this invention, there is illustrated a centrifugal purifier wherein contaminants are separated from a fluid by means of centrifugal force. The fluid and entrained contaminants are centrifuged by a rotating impeller contained within an impeller cavity. The centrifugal force drives contaminants radially outwardly into the cavity. A perforate member is interposed between fluid inlet and fluid outlet means that communicate with the cavity and has openings sized to exclude particles greater than a predetermined size to assist in the separating function. Bypass openings are provided in the perforate member to permit bypassing of it should it become clogged. Although this type of device is highly useful in excluding substantially all particles greater than a predetermined size, it is not 100% effective in removing such particles. All particles may be removed by eliminating the bypass opening; however, the flow resistance of the perforate member when it becomes clogged could then cut off or starve the fluid system in which it is interposed.

It is, therefore, a principal object of this invention to provide a centrifugal purifier of the type disclosed that will remove all particles larger than a predetermined size from the fluid system but will not restrict fluid flow when the device becomes clogged with contaminants.

It is a further object of this invention to provide a bypass valve for a centrifugal purifier of the type described.

A centrifugal purifier embodying this invention comprises housing means defining a fluid cavity. An annular perforate member is supported for rotation within the cavity. The perforate member has finely spaced openings sized to exclude particles greater than a predetermined size from fluid passing through the perforate member. Fluid inlet means opens into the cavity radially outwardly of the perforate member and fluid outlet means opens into the cavity radially inwardly of the perforate member so that all of the fluid flowing through the cavity passes through the perforate member. A normally closed bypass passage is provided between the fluid inlet means and fluid outlet means for bypassing the perforate member and means are provided for permitting flow through the by- Patented Oct. 17, 1967 pass means when the perforate member becomes clogged with contaminants.

Other objects and advantages of this invention will become more apparent as this description proceeds, particularly when considered in conjunction With the acc0mpanying drawings, wherein:

FIGURE 1 is a front elevational view of a centrifugal purifier embodying this invention; and

FIGURE 2 is an enlarged partial cross-sectional view taken generally along the line 2-2 of FIGURE 1.

Referring now in detail to the drawings, a centrifugal purifier embodying this invention is identified generally by the reference numeral 11. The centrifugal purifier 11 has many features in common with that disclosed in the aforementioned copending patent application and reference may be had to that application for specific details not disclosed herein because they form no part of the present invention. The centrifugal purifier 11 includes an outer shell made up of a housing 12 and cover plate 13. The housing 12 and cover plate 13 are affixed together by means of a clamp assembly 14 that engages upstanding circumferential ribs 15 and 16 of the cover plate 13 and housing 12, respectively. An O-ring seal 17 is compressed Within an annular groove 18 formed in the cover plate 13 by means of a chamfered shoulder 19 formed at one end of the housing 12.

The cover plate 13 is provided with a flanged mounting portion 21 that is adapted to be affixed to an engine or other prime mover. A drive shaft 22 is journaled within the cover plate 13 and has a splined end 23 that is adapted to be fixed in driving engagement with the prime mover. The internal support for the drive shaft 22 and seals which preclude leakage from the purifier 11 around the drive shaft 22 form no part of this invention and, hence, may be considered conventional in structure.

A fluid inlet fitting 24 and fluid outlet fitting 25 are formed integrally within the cover plate 13 so that fluid may be admitted and discharged from the purifier assembly 11. The fluid inlet fitting 24 and fluid outlet 25 communicate by means of suitable flow passages with an annular cavity 26 defined within the housing 12 and with a centrifuge assembly, indicated generally by the reference numeral 27.

The centrifuge assembly 27 is comprised of a first generally cup-shaped housing 28 having a beveled outer end 29 that engages a similar beveled end 31 of a second cup-shaped member 32. The cup-shaped housings 28 and 32 define an annular fluid cavity 33 in which entrained contaminants are centrifuged from a fluid as will become more apparent as this description proceeds.

A pilot shaft 35 has a male threaded end 36 that is threaded into a tapped hole 37 formed concentrically within the housing 12. A bearing member 38 is positioned coaxially upon the pilot shaft 35 and a driving sleeve 39 is journaled upon the bearing member 38. The driving sleeve 39 is splined or connected in any other suitable manner (not shown) to the drive shaft 22 and may be formed integrally with the cup-shaped member 32. The drive sleeve 39 has a male threaded end 41 that is received in a tapped hole 42 formed in a hub member 4-3. An O-ring seal 44 is compressed between the outer end of the hub member 43 and an adjacent surface of the centrifuge cover member 28 to effect a fluid tight seal in this area.

A generally cup-shaped inner shell 45 is aflixed to the remainder of the centrifuge assembly 27 by means of a plurality of circumferentially spaced screws 46 that extend through apertures formed in a radially inwardly extending flange 47 of the inner shell 45. An enlarged flange 48 formed at the other end of the inner shell 45 is provided with tapped holes that receive bolts 49 that affix the second cup-shaped member 32 to the inner shell 45. An annular gasket 51 is interposed between the flange 48 and cup-shaped member 32 to preclude leakage in this area.

A tubular member 52 forms an annular fluid passage 53 coaxially around the pilot shaft and driving hub 43. The tubular member 52 is provided with an outwardly extending flange that is engaged by a snap ring 54 which is, in turn, received in a circumferential groove 55 in the inner shell to aflix the tubular member 52 axially with respect to the remainder of the centrifuge assembly 27. The annular passage 53 forms a fluid inlet passage that is in fluid communication with the fluid inlet fitting 24 by means of suitable fluid passage (not shown) formed in the cover plate 13. Impeller blades (not shown) are formed integrally with the driving hub 43 extending to the annular fluid passage 53 to impart a centrifugal force to the fluid and entrained contaminants within the centrifuge assembly 27.

The inner end of the annular fluid passage 53 joins a plurality of radially extending fluid passages 56 that connect the passage 53 with the portion of the fluid chamber 33 between the inner shell 45 and the cup-shaped members 28 and 32. Fluid outlet openings 57 are formed in the forward end of the cup-shaped member 32 and communicate with the fluid outlet fitting 25 by means of suitable passages (not shown) formed in the cover plate 13. Fluid is normally circulated through the purifier 11 by means of an external pump (not shown).

The centrifugal force generated upon the contaminants and fluid in the centrifuge assembly 11 will cause the heavier contaminants to be driven radially outwardly in the cavity 33 away from the fluid outlet opening 57 to separate the particles from the circulating fluid. If desired, a contaminant repository 58 may be formed in this area by means of a perforate annular inner shell 57 in which louvered openings 59 are provided. The heavier particles will be driven through the louvered openings 59 into the contaminant repository 58 to preclude reentry into the fluid system.

The use of a centrifugal force to exclude the heavier particles from the fluid provides a very effective filter. In some instances, however, it is desired to exclude all particles larger than a predetermined size. The size of the particles excluded by a centrifugal purifier per se depends upon such variables as the density of the particles, the viscosity of the fluid being circulated, the speed of the impeller and other similar factors. It is difficult to maintain all of these factors constant.

A perforate member or screen 62 of generally conical shape is supported by a conical member 63 having openings 64 formed in it. The screen 62 is interposed between the fluid passage 56, which may be considered a fluid inlet passage, and the fluid outlet passage 57. The conical member 63 has a hub portion 65 that is sealingly engaged with an O-ring gasket 66 interposed between it and the inner shell 45. A cylindrical portion 67 at the other end of the perforate member 63 engages the flange portion 48 of the inner shell 45.

Since the screen 62 is aflixed to the rotating components of the centrifuge assembly 27, small particles which are trapped by the perforations in it will tend to be driven radially outwardly by the centrifugal force. This, in effect, provides some self-cleaning for the screen 62. It is, of course, possible that the screen 62 will become clogged due to the entrapment of a large number of small particles. When this occurs, the flow resistance through the centrifuge assembly 11 could increase sufliciently to retard the fluid flow in the system. It should be noted that the centrifuge assembly 11, although it provides some boost in fluid pressure, is primarily intended for use in a system wherein pressurized fluid flows through it.

A bypass device is provided for bypassing the screen 62 when the pressure differential across it exceeds a predetermined value. The bypass device comprises a plurality of circumferentially spaced openings 71 (only one of which is shown) formed in the flange 47 of the inner shell 45. The openings 71 are normally closed by an annular gasket 72 that is affixed to an open bottom cupshaped valve member 73 having a pair of cylindrical flanges 74 that slidingly engage the inner periphery of the inner shell 45. A coil compression spring 75 engages the cup-shaped valve member 73 and circumferentially spaced inwardly extending fingers 76 formed integrally with the tubular member 52.

When the flow resistance of the screen 62 exceeds a predetermined value, the pressure acting upon the gasket 72 through the fluid openings 71 will exceed the precompression of the coil spring 75 and urge the valve member 73 away from registry with the openings 71. Fluid may then flow past the gasketed valve member 73 around the clearance between the tubular member 72 and the valve member 73 to the fluid outlet openings 57 through circumferentially spaced bypass passages 77 formed at one end of the tubular member 52. When this condition occurs, the centrifuge assembly 11 should be disassembled and cleaned. It is to be understood, however, that the purification provided by the centrifugal action of the purifier will still be fully effective. The smaller particles which the screen 62 excludes will, however, escape past the purifier 11.

While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. A centrifugal purifier for separating contaminants having a size larger than a predetermined size from a fluid comprising housing means defining fluid cavity means, a rotating impeller for imparting a centrifugal force to the fluid and entrained contaminants in said cavity means, fluid inlet means and fluid outlet means opening into said cavity for fluid flow through said cavity, a perforate member interposed between said fluid inlet means and said fluid outlet means for flow of substantially all of the fluid flowing through said cavity means through said perforate member, said perforate member having finely spaced openings sized to exclude particles greater than a predetermined size from the fluid flowing through said perforate member, said impeller and said perforate member being disposed in series flow relationship wherein fluid normally flows first past said impeller and then past said perforate member, and normally closed bypass means for bypassing the fluid flow from said fluid inlet means to said fluid outlet means past only said perforate member when said perforate member becomes clogged with contaminants without effecting the flow past said impeller for removal of contaminants from the fluid by said impeller when said perforate member is bypassed.

2. A centrifugal purifier for separating contaminants having a size larger than a predetermined size from a fluid comprising housing means defining fluid cavity means, a rotating impeller for imparting a centrifugal force to the fluid and entrained contaminants in said cavity means, an annular perforate member positioned within said cavity means, fluid inlet means and fluid outlet means opening into said cavity on opposite radial sides of said perforate member whereby substantially all of the fluid flowing from said fluid inlet means to said fluid outlet means passes radially through said perforate member, said impeller and said perforate member being disposed in series flow relationship wherein fluid normally flows first past said impeller and then past said perforate member, and normally closed bypass means for bypassing fluid flow directly from said fluid inlet means to said fluid outlet means past only said perforate member when said perforate member is clog ed with contaminants without effecting the flow past said impeller for removal of contaminants from the fluid by said impeller when said perforate member is bypassed.

3. A centrifugal purifier for separating contaminants having a size larger than a predetermined size from a fluid comprising housing means defining fluid cavity means, a rotating impeller for imparting a centrifugal force to the fluid and entrained contaminants in said cavity means, an annular perforate member supported for rotation Within said cavity means, said perforate member having finely spaced openings sized to exclude particles greater than a predetermined size from the fluid flowing through said perforate member, fluid inlet means opening into said cavity radially outwardly from said perforate member, fluid outlet means opening into said cavity radially inwardly of said perforate member whereby substantially all of the fluid flowing from said fluid inlet means to said fluid outlet means passes radially inwardly through said perforate member, said impeller and said perforate member being disposed in series flow relationship wherein fluid normally flows first past said impeller and then past said perforate member, means for rotating said perforate member for driving the particles separated from the fluid by said perforate member away from said perforate member, and normally closed fluid bypass means for bypassing fluid flow directly from said fluid inlet means to said fluid outlet means past only said perforate member when said perforate member becomes clogged with contaminants without effecting the flow past said impeller for removal of contaminants from the fluid by said impeller when said perforate member is bypassed.

4. A centrifugal purifier as set forth in claim 3 wherein the bypass means includes pressure responsive valve means.

5. A centrifugal purifier for separating contaminants having a size larger than a predetermined size from a fluid comprising housing means defining a fluid cavity, a rotating impeller for imparting a centrifugal force to the fluid and entrained contaminants in said cavity, an annular perforate member supported for rotation within said cavity, said perforate member having finely spaced openings sized to exclude particles greater than a predetermined size from fluid flowing through said perforate member, fluid inlet means opening into said cavity radially outwardly of said perforate member, fluid outlet means opening into said cavity radially inwardly of said perforate member whereby substantially all of the fluid flowing from said fluid inlet means to said fluid outlet means passes radially through said perforate member, said impeller and said perforate member being disposed in series flow relationship wherein fluid normally flows first past said impeller and then past said perforate member, means for affixing said perforate member to said impeller for simultaneous rotation of said impeller and said perforate member for driving the particles separated from the fluid by said perforate member away from said perforate member, and normally closed fluid bypass means for bypassing fluid flow directly from said fluid inlet means to said fluid outlet means past only said perforate member when said perforate member becomes clogged with contaminants without effecting the flow past said impeller for removal of contaminants from the fluid by said impeller when said perforate member is bypassed.

6. A centrifugal purifier as set forth in claim 5 wherein the bypass means includes pressure responsive valve means.

7. A centrifugal purifier for separating contaminants having a size larger than a predetermined size from a fluid comprising housing means defining a fluid cavity, a rotating impeller for imparting a centrifugal force to the fluid and entrained contaminants in said cavity, fluid inlet means opening into said cavity, fluid outlet means opening into said outlet cavity, a perforate member interposed between said fluid inlet means and said fluid outlet means 6 whereby substantially all of the fluid flowing therebe'tween passes through said perforate member, said perforate member having finely spaced openings sized to exclude particles greater than the predetermined size from fluid flowing through said perforate member, said impeller and said perforate member being disposed in series flow relationship wherein fluid normally flows both past said impeller and past said perforate member, an annular contaminant repository encircling said impeller and in fluid communication with said fluid cavity for receiving and retaining particles driven from said cavity by the centrifugal force generated by said impeller, and normally closed fluid bypass means for bypassing fluid flow directly from said fluid inlet means to said fluid outlet means past only said perforate member when said perforate member becomes clogged with contaminants without effecting the flow past said impeller for removal of contaminants from the fluid by said impeller when said perforate member is bypassed.

8. A centrifugal purifier for separating contaminants having a size larger than a predetermined size from a fluid comprising housing means defining a fluid cavity, a rotating impeller for imparting a centrifugal force to the fluid and entrained contaminants in said cavity, an annular perforate member extending across said cavity, said perforate member having finely spaced openings sized to exclude particles greater than the predetermined size from fluid flowing through said perforate member, fluid inlet means and fluid outlet means opening into said cavity at different radial locations with respect to said perforate member whereby fluid flows radially through said perforate member, said impeller and said perforate member being disposed in series flow relationship wherein fluid normally flows both past said impeller and past said perforate member, an annular contaminant repository encircling said perforate member and in fluid communication with said fluid cavity for receiving and retaining the particles driven from said fluid cavity by said impeller, and normally closed bypass means for bypassing fluid directly from said fluid inlet means to said fluid outlet means past only said perforate member when said perforate member becomes clogged with contaminants without effecting the flow past said impeller for removal of contaminants from the fluid by said impeller when said perforate member is bypassed.

9. A centrifugal purifier as set forth in claim 8 wherein the bypass means includes pressure responsive valve means.

10. A centrifugal purifier for separating contaminants having a size larger than a predetermined size from a fluid comprising housing means defining a fluid cavity, a rotating impeller for imparting a centrifugal force to the fluid and entrained contaminants in said cavity, an annular perforate member surrounding said impeller within said cavity, said perforate member having finely spaced openings sized to exclude particles greater than a predetermined size from fluid flowing through said impeller, fluid inlet means opening into said cavity radially outwardly of said perforate member, fluid outlet means opening into said cavity radially inwardly of said perforate member whereby substantially all of the fluid flowing from said fluid inlet means to said fluid outlet means passes radially inwardly through said perforate member, said impeller and said perforate member being disposed in series flow relationship wherein fluid normally flows both past said impeller and past said perforate member, an annular contaminant repository encircling said perforate member and in fluid communication with said fluid cavity for receiving and retaining the particles driven from said fluid cavity by said impeller, means affixing said perforate member to said impeller for simultaneous rotation of said impeller and said perforate member, and normally closed bypass means for bypassing fluid directly from said fluid inlet means to said fluid outlet means past only said perforate member when said perforate member becomes clogged with contaminants with 7 out effecting the flow past said impeller for removal of contaminants from the fluid by said impeller when said perforate member is bypassed.

11. A centrifugal purifier as set forth in claim 10 Wherein the bypass means comprise fluid passage means inter connecting the fluid inlet means with the fluid outlet means and pressure responsive valve means for controlling the flow through said fluid passage means.

References Cited UNITED STATES PATENTS 8 VOkes 210-130 More 233-2 Corteggiani 2332 Darnell 23331 Darnell 210130 X Downey 233-2 FOREIGN PATENTS Canada.

REUBEN FRIEDMAN, Primary Examiner.

1. DE CESARE, Assistant Examiner. 

1. A CENTRIFUGAL PURIFIER FOR SEPARATING CONTAMINANTS HAVING A SIZE LARGER THAN A PREDETERMINED SIZE FROM A FLUID COMPRISING HOUSING MEANS DEFINING FLUID CAVITY MEANS, A ROTATING IMPELLER FOR IMPARTING A CENTRIFUGAL FORCE TO THE FLUID AND ENTRAINED CONTAMINANTS IN SAID CAVITY MEANS, FLUID INLET MEANS AND FLUID OUTLET MEANS OPENING INTO SAID CAVITY FOR FLUID FLOW THROUGH SAID CAVITY, A PERFORATE MEMBER INTERPOSED BETWEEN SAID FLUID INLET MEANS AND SAID FLUID OUTLET MEANS FOR FLOW OF SUBSTANTIALLY ALL OF THE FLUID FLOWING THROUGH SAID CAVITY MEANS THROUGH SAID PERFORATE MEMBER, SAID PERFORATE MEMBER HAVING FINELY SPACED OPENINGS SIZED TO EXCLUDE PARTICLES GREATER THAN A PREDETERMINED SIZE FROM THE FLUID FLOWING THROUGH SAID PERFORATE MEMBER, SAID IMPELLER AND SAID PERFORATE MEMBER BEING DISPOSED IN SERIES FLOW RELATIONSHIP WHEREIN FLUID NORMALLY FLOWS FIRST PAST SAID IMPELLER AND THEN PAST SAID PERFORATE MEMBER, AND NORMALLY CLOSED BYPASS MEANS FOR BYPASSING THE FLUID FLOW FROM SAID FLUID INLET MEANS TO SAID FLUID OUTLET MEANS PAST ONLY SAID PERFORATE MEMBER WHEN SAID PERFORATE MEMBER BECOMES CLOGGED WITH CONTAMINANTS WITHOUT EFFECTING THE FLOW PAST SAID IMPELLER FOR REMOVAL OF CONTAMINANTS FROM THE FLUID BY SAID IMPELLER WHEN SAID PERFORATE MEMBER IS BYPASSED. 